Spray arm assemblies for dishwasher appliances

ABSTRACT

Spray arm assemblies for dishwasher appliances are provided. In some embodiments, a spray arm assembly includes a first spray arm, the first spray arm including an inner arm member and an outer arm member, the inner arm member defining an interior and extending along a longitudinal axis, the outer arm member generally concentric with and surrounding the inner arm member. The inner arm member is rotatable about the longitudinal axis. The inner arm member defines an inner slot extending helically along the longitudinal axis. The outer arm member defines an outer slot extending generally linearly along the longitudinal axis.

FIELD OF THE INVENTION

The present disclosure relates generally to dishwasher appliances, and more particularly to improved spray arm assemblies for dishwasher appliances.

BACKGROUND OF THE INVENTION

Dishwasher appliances generally include a tub that defines a wash compartment. Rack assemblies can be mounted within the wash compartment of the tub for receipt of articles for washing. During wash and rinse cycles, spray assemblies within the wash compartment can apply or direct wash fluid (e.g. various combinations of water and detergent along with optional additives) towards articles disposed within the rack assemblies in order to clean such articles.

Multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash compartment, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash compartment. Other configurations may be used as well.

One limitation of many currently known spray arm assemblies is the geometry of the spray arm assemblies relative to the geometry of the dishwasher appliance interior. Most known spray arm assemblies utilize a generally circular geometry. For example, an arm of a spray arm assembly may rotate in a circle, and jets or apertures defined in the arm may emit wash fluid from the arm in this circular pattern. Each jet emits fluid in a constant direction from the associated arm during rotation, so that the locations reached by the wash fluid are predictable and limited. Further, the cross-sectional interior geometry of most currently known dishwasher appliances is square or rectangular. Accordingly, the corners of such dishwasher appliance, and the articles located therein, may not be sufficiently reached by wash fluid. These limitations can result in articles not being properly cleaned during operation of the dishwasher appliance.

Accordingly, improved spray arm assemblies and associated dishwasher appliances are desired in the art. In particular, improved spray arm assembly designs which increase the coverage of the wash fluid emitted therefrom would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In accordance with one embodiment of the present disclosure, a spray arm assembly for a dishwasher appliance is provided. The spray arm assembly includes a first spray arm, the first spray arm including an inner arm member and an outer arm member, the inner arm member defining an interior and extending along a longitudinal axis, the outer arm member generally concentric with and surrounding the inner arm member. The inner arm member is rotatable about the longitudinal axis, and defines an inner slot extending helically along the longitudinal axis. The outer arm member defines an outer slot extending generally linearly along the longitudinal axis.

In accordance with another embodiment of the present disclosure, a spray arm assembly for a dishwasher appliance is provided. The spray arm assembly includes a first spray arm, the first spray arm including an inner arm member and an outer arm member, the inner arm member defining an interior and extending along a longitudinal axis, the outer arm member generally concentric with and surrounding the inner arm member. The inner arm member is rotatable about the longitudinal axis. The spray arm assembly further includes a central housing defining and rotatable about a central axis, the central axis generally perpendicular to the longitudinal axis. The spray arm assembly further includes a bevel gear assembly disposed within the central housing. The bevel gear assembly is configured to rotate the inner arm member about the longitudinal axis when the central housing rotates about the central axis. The bevel gear assembly includes a drive gear, an axle gear, and an idler gear, the axle gear mounted to the inner arm member.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 provides a front view of a dishwasher appliance in accordance with one embodiment of the present disclosure;

FIG. 2 is a side cross-sectional view of a dishwasher appliance in accordance with one embodiment of the present disclosure;

FIG. 3 is a top view of a spray arm assembly in accordance with one embodiment of the present disclosure;

FIG. 4 is a top view of a spray arm assembly, with outer arm members of first spray arms and arm members of second spray arms in phantom for illustrative purposes, in accordance with one embodiment of the present disclosure;

FIG. 5 is a perspective close-up view of central portions of a spray arm assembly, with a central housing, outer arm members of first spray arms, and arm members of second spray arms in phantom for illustrative purposes, in accordance with one embodiment of the present disclosure; and

FIG. 6 is a cross-sectional view of central portions of a spray arm assembly, with a central housing and outer arm members of first spray arms in phantom for illustrative purposes, in accordance with one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the term “article” may refer to but need not be limited to dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during which a dishwashing appliance operates while containing the articles to be washed and uses a detergent and water, preferably with agitation, to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time in which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “wash fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include other additives such as detergent or other treatments.

FIGS. 1 and 2 depict an exemplary domestic dishwasher or dishwashing appliance 100 that may be configured in accordance with aspects of the present disclosure. For the particular embodiment of FIGS. 1 and 2, the dishwasher 100 includes a cabinet 102 having a tub 104 therein that defines a wash chamber 106. The tub 104 includes a front opening (not shown) and a door 120 hinged at its bottom 122 for movement between a normally closed vertical position (shown in FIGS. 1 and 2), wherein the wash chamber 106 is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher. Latch 123 is used to lock and unlock door 120 for access to chamber 106.

Upper and lower guide rails 124, 126 are mounted on tub side walls 128 and accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in FIG. 2). Each rack 130, 132 is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2) in which the rack is located inside the wash chamber 106. This is facilitated by rollers 135 and 139, for example, mounted onto racks 130 and 132, respectively. A silverware basket (not shown) may be removably attached to rack assembly 132 for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks 130, 132.

The dishwasher 100 further includes a lower spray-arm assembly 144 that is rotatably mounted within a lower region 146 of the wash chamber 106 and above a tub sump portion 142 so as to rotate in relatively close proximity to rack assembly 132. A mid-level spray-arm assembly 148 is located in an upper region of the wash chamber 106 and may be located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 may be located above the upper rack 130.

The lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 are fed by a fluid circulation assembly 152 for circulating water and dishwasher fluid in the tub 104. The fluid circulation assembly 152 may include a pump 154 located in a machinery compartment 140 located below the bottom sump portion 142 of the tub 104, as generally recognized in the art. Each spray-arm assembly 144, 148 includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in rack assemblies 130 and 132. The arrangement of the discharge ports, also referred to as jets or apertures, in spray-arm assemblies 144, 148 provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly 144 provides coverage of dishes and other dishwasher contents with a washing spray.

The dishwasher 100 is further equipped with a controller 137 to regulate operation of the dishwasher 100. The controller may include a memory and one or more microprocessors, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.

The controller 137 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, the controller 137 may be located within a control panel area 121 of door 120 as shown. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher 100 along wiring harnesses that may be routed through the bottom 122 of door 120. Typically, the controller 137 includes a user interface panel 136 through which a user may select various operational features and modes and monitor progress of the dishwasher 100. In one embodiment, the user interface 136 may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface 136 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface 136 may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface 136 may be in communication with the controller 137 via one or more signal lines or shared communication busses.

Referring now to FIGS. 3 through 6, various embodiments of a spray arm assembly 200 are illustrated. A spray arm assembly 200 may be utilized in a dishwasher appliance 100, and advantageously may provide increased coverage for wash fluid emitted therefrom within the dishwasher appliance 100.

In exemplary embodiments, the spray arm assembly 200 is a lower spray arm assembly 144. Alternatively, the spray arm assembly 200 may be a mid-level spray arm assembly 148 or may be utilized in the place of an upper spray assembly 150, or may be utilized in any other suitable position within dishwasher appliance 100. The spray arm assembly 200 may generally be in fluid communication with the fluid circulation assembly 152 to receive wash fluid therefrom. The wash fluid is then flowed through the spray arm assembly 200 and exhausted therefrom into the wash chamber 106 during operation of the dishwasher appliance 100, such as during a wash or rinse cycle.

Spray arm assembly 200 may include one or more spray arms. For example, as illustrated, spray arm assembly 200 may include one or more first spray arms 202. Each first spray arm 202 may include an inner arm member 204. Inner arm member 204 may define an interior 206. Further, inner arm member 204 may extend along and define a longitudinal axis 208, and may extend between a base 210 and a tip 212 along the longitudinal axis 208. A first spray arm 202 may further include an outer arm member 214. The outer arm member 214 may define an interior 216, and may generally surround the inner arm member 204 such that the inner arm member 204 (or at least a substantial portion thereof) is disposed within the interior 216. Outer arm member 214 may extend between a base 220 and a tip 222. Further, outer arm member 214 may be generally concentric with the inner arm member 204, and thus similarly extend along the longitudinal axis 208 defined by the inner arm member 204.

Spray arm assembly 200 may further include a central housing 230 that defines an interior 232. The central housing 230 may further define a central axis 234 therethrough, which may for example be generally perpendicular to the longitudinal axis or axes 208 of the inner arm member(s) 204. Central housing 230 may, for example, be rotatable about the central axis 234.

Housing 230 may be in fluid communication with the fluid circulation assembly 152 to receive wash fluid therefrom. Accordingly, wash fluid may flow into the housing 230 though inlet 236. The wash fluid may then flow from the housing 230 to the various spray arms of the spray arm assembly 200, including for example the first spray arms 202 and second spray arms as discussed herein.

A first spray arm 202 in accordance with the present disclosure may further operate to emit wash fluid therefrom in an improved manner which advantageously increases the wash fluid coverage within the dishwasher appliance 100. For example, inner arm member 204 may be rotatable about the longitudinal axis 208. Apertures or slots, as discussed herein, may be defined in the inner arm member 204 to emit wash fluid therethrough from the interior 206 of the inner arm member 204. The inner arm member 204 may, for example, be in fluid communication with the housing 230 such that wash fluid flows from the interior 232 into the interior 206. This wash fluid can then be emitted through the apertures or slots.

Outer arm member 214 may, for example, be generally stationary relative to the longitudinal axis 208. For example, the outer arm member 214, such as the base 220 thereof, may be mounted to the central housing 230. In some embodiments, the outer arm member 214 may be integral with the central housing 230, while in other embodiments the outer arm member 214 may be a separate component connected to the central housing 230 via a suitable adhesive, mechanical fastener, etc. Apertures or slots, as discussed herein, may be defined in the outer arm member 214 to emit wash fluid therethrough from the interior 216 of the outer arm member 214. The outer arm member 214 may, for example, be in fluid communication with the inner arm member 204 such that wash fluid flows from the interior 206 into the interior 216. This wash fluid can then be emitted through the apertures or slots.

In exemplary embodiments, as shown, inner arm member 204 may define one or more inner slots 240, which may extend along at least a portion of the inner arm member 204 between the base 210 and the tip 212. The slot 240 may be in fluid communication with the interior 206, and thus allow wash fluid to flow from the interior 206 therethrough to exit the inner arm member 204. Further, in exemplary embodiments, the inner slot 240 may be a helical inner slot 240, thus extending helically along the longitudinal axis 208 as shown.

Further, in exemplary embodiments, as shown, the outer arm member 214 may define one or more outer slots 242, which may extend along at least a portion of the outer arm member 214 between the base 220 and the tip 222. The slot 242 may be in fluid communication with the interior 216, and thus allow wash fluid to flow from the interior 216 therethrough to exit the outer arm member 214. Further, in exemplary embodiments, the outer slot 242 may be a generally linear outer slot 242, thus extending generally linearly along the longitudinal axis 208 as shown.

Accordingly, in for example embodiments wherein the inner arm member 204 includes a helical inner slot 240 and the outer arm member 214 includes a generally linear outer slot 242, rotation of the inner arm member 204 about the longitudinal axis 208 and relative to the outer arm member 214 may cause different portions of the slot 240 to align with the outer slot 242 at different times during operation. This may thus cause the wash fluid to be emitted from the outer arm member 214 at a variety of locations along outer slot 242 during operation, thus advantageously providing increased wash fluid coverage.

As discussed, inner arm members 204 in accordance with the present disclosure may be rotatable about their longitudinal axes 208. In exemplary embodiments, a gear assembly 250 may be disposed within the central housing 230. Gear assembly 250 may be configured to rotate the inner arm member(s) 204 about their longitudinal axes 208. In exemplary embodiments, a gear assembly 250 may be configured to rotate inner arm member(s) 204 about their longitudinal axes 208 when the central housing 230 rotates about the central axis 234, and due to this rotation.

For example and as shown, gear assembly 250 may be a bevel gear assembly 250, with the various gears thereof having a bevel-style arrangement. Gear assembly 250 may include, for example, a drive gear 252 and one or more axle gears 254. Each axle gear 254 may be mounted to an associated inner arm member 204. In some embodiments, an axle gear 254 may be integral with the associated inner arm member 206, while in other embodiments the axle gear 254 may be a separate component connected to the associated inner arm member 204 via a suitable adhesive, mechanical fastener, etc.

Gear teeth 253 of the drive gear 252 may mesh with gear teeth 255 of the axle gears 254, and the drive gear 252 may drive the axle gears 254. Rotation of an axle gear 254 may cause rotation of the associated inner arm member 204 about its longitudinal axis 208. For example, central housing 230 and the first spray arms 202 and associated axle gears 254 may be rotatable about the central axis 234 relative to the drive gear 252. Due to the meshing of the drive gear 252 and axle gears 254, this rotation may cause the drive gear 252 to drive rotation of the axle gears 254 about the associated longitudinal axes 208 of the associated inner arm members 204, thus causing rotation of the associated inner arm members 204 about their longitudinal axes 208.

Further, in some embodiments, the number of gear teeth 255 of an axle gear 254 may be different from the number of gear teeth 253 of a drive gear 252. In exemplary embodiments, the number of gear teeth 255 of an axle gear 254 may be less than the number of gear teeth 253 of a drive gear 252. Alternatively, the number of gear teeth 255 of an axle gear 254 may be more than the number of gear teeth 253 of a drive gear 252. The resulting gear ratio may advantageously cause the location of emitted wash fluid along an outer arm member 214 to be varied for each location of the outer arm member 214 during rotation about the central axis 234, thus advantageously providing increased wash fluid coverage.

In some embodiments, gear assembly 250 may further include an idler gear 256, as shown, which may include gear teeth 257 that mesh with teeth 255 of axle gears 254. Idler gear 256 may advantageously provide stability to the gear assembly 250 and reduce binding during operation thereof.

As further illustrated, spray arm assembly 200 may include one or more second spray arms 260. Each second spray arm 260 may include an arm member 262. Arm member 262 may define an interior 264. Further, arm member 262 may extend along and define a longitudinal axis 266, and may extend between a base 270 and a tip 272 along the longitudinal axis 266.

Arm member 262 may, for example, be generally stationary relative to the longitudinal axis 266. For example, the arm member 262, such as the base 270 thereof, may be mounted to the central housing 230. In some embodiments, the arm member 262 may be integral with the central housing 230, while in other embodiments the arm member 262 may be a separate component connected to the central housing 230 via a suitable adhesive, mechanical fastener, etc. Apertures or slots, as discussed herein, may be defined in the arm member 262 to emit wash fluid therethrough from the interior 264 of the arm member 262. The arm member 264 may, for example, be in fluid communication with the central housing 230 such that wash fluid flows from the interior 232 into the interior 264. This wash fluid can then be emitted through the apertures or slots.

In exemplary embodiments as shown, the arm member 262 of a second spray arm 260 may define one or more apertures 276. In particular the apertures 276 may be drive jet apertures 276, which may emit wash fluid at an orientation that drives rotation of the spray arm 260, and thus the central housing 230 and first spray arms 202, about the central axis 232. In exemplary embodiments, as shown, aperture(s) 276 may be disposed proximate the tip 272 of the arm member 262.

First and second spray arms 202, 260 may have any suitable arrangement about central axis 234. For example, in exemplary embodiments when more than one first spray arm 202 is utilized, the spray arms 202 may be arrayed about the central axis 234, such as generally equally spaced apart about the central axis 234. For example, two first spray arms 202 may be spaced approximately 180 degrees apart from each other about the central axis 234, three first spray arms 202 may be spaced approximately 120 degrees apart from each other about the central axis 234, four first spray arms 202 may be spaced approximately 90 degrees apart from each other about the central axis 234, etc. Similarly, in exemplary embodiments when more than one second spray arm 260 is utilized, the spray arms 260 may be arrayed about the central axis 234, such as generally equally spaced apart about the central axis 234. For example, two second spray arms 260 may be spaced approximately 180 degrees apart from each other about the central axis 234, three second spray arms 260 may be spaced approximately 120 degrees apart from each other about the central axis 234, four second spray arms 260 may be spaced approximately 90 degrees apart from each other about the central axis 234, etc. Additionally, in exemplary embodiments wherein both first and second spray arms 202, 260 are utilized, all spray arms 202, 260 may be arrayed about the central axis 234, such as generally equally spaced apart about the central axis 234. Further, in exemplary embodiments wherein both first and second spray arms 202, 260 are utilized, the arms 202, 260 may for example be arrayed in an alternating manner about the central axis 234.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A spray arm assembly for a dishwasher appliance, the spray arm assembly comprising: a first spray arm, the first spray arm comprising an inner arm member and an outer arm member, the inner arm member defining an interior and extending along a longitudinal axis, the outer arm member generally concentric with and surrounding the inner arm member, the inner arm member rotatable about the longitudinal axis, the inner arm member defining an inner slot extending helically along the longitudinal axis, the outer arm member defining an outer slot extending generally linearly along the longitudinal axis.
 2. The spray arm assembly of claim 1, further comprising a central housing defining a central axis, the central axis generally perpendicular to the longitudinal axis.
 3. The spray arm assembly of claim 2, wherein the outer arm member is mounted to the central housing.
 4. The spray arm assembly of claim 2, wherein the central housing is rotatable about the central axis.
 5. The spray arm assembly of claim 4, further comprising a gear assembly disposed within the central housing, the gear assembly configured to rotate the inner arm member about the longitudinal axis when the central housing rotates about the central axis.
 6. The spray arm assembly of claim 5, wherein the gear assembly is a bevel gear assembly, the bevel gear assembly comprising a drive gear and an axle gear, the axle gear mounted to the inner arm member.
 7. The spray arm assembly of claim 6, wherein the bevel gear assembly further comprises an idler gear.
 8. The spray arm assembly of claim 6, wherein the number of gear teeth of the axle gear is less than the number of gear teeth of the drive gear.
 9. The spray arm assembly of claim 1, wherein the first spray arm is a plurality of first spray arms.
 10. The spray arm assembly of claim 1, further comprising a second spray arm, the second spray arm comprising an arm member defining an interior, the arm member defining an aperture.
 11. The spray arm assembly of claim 10, wherein the aperture is disposed proximate a tip of the arm member of the second spray arm.
 12. A spray arm assembly for a dishwasher appliance, the spray arm assembly comprising: a first spray arm, the first spray arm comprising an inner arm member and an outer arm member, the inner arm member defining an interior and extending along a longitudinal axis, the outer arm member generally concentric with and surrounding the inner arm member, the inner arm member rotatable about the longitudinal axis; a central housing defining and rotatable about a central axis, the central axis generally perpendicular to the longitudinal axis; and a bevel gear assembly disposed within the central housing, the bevel gear assembly configured to rotate the inner arm member about the longitudinal axis when the central housing rotates about the central axis, the bevel gear assembly comprising a drive gear, an axle gear, and an idler gear, the axle gear mounted to the inner arm member.
 13. The spray arm assembly of claim 12, wherein the outer arm member is mounted to the central housing.
 14. The spray arm assembly of claim 12, wherein the number of gear teeth of the axle gear is less than the number of gear teeth of the drive gear.
 15. The spray arm assembly of claim 12, wherein the inner arm member defines an inner slot extending helically along the longitudinal axis.
 16. The spray arm assembly of claim 12, wherein the outer arm member defines an outer slot extending generally linearly along the longitudinal axis.
 17. The spray arm assembly of claim 12, wherein the first spray arm is a plurality of first spray arms.
 18. The spray arm assembly of claim 12, further comprising a second spray arm, the second spray arm comprising an arm member defining an interior, the arm member defining an aperture.
 19. The spray arm assembly of claim 18, wherein the aperture is disposed proximate a tip of the arm member of the second spray arm.
 20. The spray arm assembly of claim 18, wherein the second spray arm is mounted to the central housing. 